Incrementing VERSION to 126.0.6478.242

Change-Id: Ieebc46c2e270dc74d90ab3fd81e0041fc7b20e3b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5780670
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/6478@{#1917}
Cr-Branched-From: e6143acc-refs/heads/main@{#1300313}